碎裂QRS波在致心律失常性右心室心肌病诊断中的价值

目的评价碎裂QRS波（fQRs波）在致心律失常性右心室心肌病（ARVC）诊断中的价值。方法43例符合ARVC诊断标准的患者,男性33例,平均年龄（40．4±13．9）岁。采集临床资料,记录静息状态下标准12导联心电图,描述fQRs波的心电图特征,判断是否存在fQRs波、epsilon波和右胸前导联T波倒置（TWI）并比较其阳性率之间的差异。结果本组患者fQRs波以下壁导联（44．3％）和右胸前导联（24．2％）最为多见。QRS波中,fQRs波见于R波者多于S波者（58．4％对32．9％,Z=4．30,P〈0．01）。共31例患者判断为fQRS波阳性,2～9（4．6±1．7）个／例。fQRs波阳性率较epsilon波（73．8％VS30．2％,Z=3．67,P〈0．01）和TWI（73．8％对41．9％,Z=2．61,P〈0．01）显著增高。结论fQRs波阳性是ARVC患者常见的心电图异常,常见于下壁和右胸前导联,可作为提示诊断的无创心电指标。     

26例致心律失常右室心肌病的临床和心电图特点分析

目的:探讨致心律失常右室心肌病(ARVC)的临床和心电图特点。方法:收集、查阅1993～2003年 上海市中山医院心内科26例诊断为ARVC的入院病例资料,分析其窦性心律和(或)室性心动过速发作时的常 规体表心电图各项参数,并作统计分析。结果:26例ARVC病例中,入院年龄为13～70(37.7±15.1)岁,首发症 状年龄为8～55(33.2±13.9)岁;13例(50%)有晕厥发作史。25例常规心电图检查中有11例(44.0%)发现Ep silon波,多见于右侧胸导联(V1～3),部分病例可出现于Ⅱ、Ⅲ和aVF导联,其中1例在大多数导联上均可见Epsi lon波;8例(33.3%)右侧胸导联可见T波倒置。右侧胸导联的平均QRS间期(QRS1=V1+V2+V3间期的平 均值)为0.1～0.22(0.13±0.030)s,左侧胸导联的平均QRS时间(QRS2=V4+V5+V6间期的平均值)为0.08 ～0.18(0.11±0.02)s(P<0.01),QRS1/QRS2为1.2±0.2(1.0～1.9),其中16例(61.5%)两者之比≥1.2。4 例出现肢体导联低电压,3例出现完全性右束支传导阻滞,类右束支、左前分支、左后分支和室内传导阻滞各1 例,1例在aVF导联出现显著的T波电交替。结论:心电图中Epsilon波和右胸导联QRS间期延长,有助于诊断 ARVC。     

体表心电图鉴别心室流出道特发性室性心动过速的起源部位

目的 :评价 12导联心电图在鉴别左室和右室流出道室性心动过速 (VT)及鉴别左室流出道VT中主动脉瓣上起源的VT和主动脉瓣下起源的VT中的价值。方法 :回顾性分析了射频消融术获得成功的 5 6例流出道特发性VT患者体表心电图特点 ,右室流出道VT组 (RVOT VT)组 4 0例 ,左室流出道VT(LVOT VT)组 16例 ,其中主动脉瓣上组 (左冠窦内 ) 10例 ,主动脉瓣下组 6例。结果 :LVOT VT组胸前导联R波移行均早于V4导联 ,87.5 %(14 / 16 )在V1或V2 导联 ,RVOT VT组 82 .5 % (33/ 4 0 )胸前导联R波移行≥V4导联 ,无一例在V3 导联前移行 ;RVOT VT组V1和V2 导联R波时限指数和R/S波幅指数明显小于LVOT VT组 [(30 .4± 12 .6 ) %∶(5 7.4± 14 .2 ) %和 (13.8± 7.5 ) %∶(5 8.2± 11.4 ) % ,均P <0 .0 1]。主动脉瓣上LVOT VT组下壁导联 (Ⅱ ,Ⅲ ,aVF)R波振幅明显高于主动脉瓣下组 ;V5和V6导联或单独V6导联有s波对确定主动脉瓣下起源的LVOT VT敏感性 10 0 % (6 / 6 ) ,V5和V6导联均无s波对确定主动脉瓣上起源的LVOT VT特异性 90 % (9/ 10 )。结论 :体表心电图对初步确定心室流出道VT的起源部位可以提供很大的帮助。     

36例致心律失常性右室心肌病的心电图特征和临床观察

目的探讨致心律失常性右室心肌病(ARVC)的心电图特征和临床表现。方法回顾分析符合欧洲心脏病协会ARVC诊断标准的36例患者的心电图参数、临床表现、超声心动图、腔内电生理检查等临床资料。结果36例中男26例、女10例,年龄37±13岁;33例表现为心悸、胸闷,11例同时伴有晕厥,2例有家族性猝死史。心电图研究发现10例(28%)出现Epsilon波,29例(81%)右胸(V1～V3)导联QRS波时限≥110ms;在29例无右束支传导阻滞的患者中,右胸导联分别有16例(55%)出现T波倒置、18例(62%)出现S波升支时间≥55ms;17例(47%)QRSd1/QRSd2(V1～V3导联与V4～V6导联QRS波时间平均值之比)≥1.2;24例(67%)出现室壁阻滞;27例(75%)记录到持续性或非持续性室性心动过速。29例超声心动图表现为严重的右室受累。25例行腔内电生理检查,20例诱发出右室起源的室性心动过速,即刻射频消融成功11例。结论ARVC好发于青年男性,是引起晕厥、室性心律失常和室壁运动异常的重要原因,Epsilon波、右胸导联QRS波时限≥110ms与T波倒置、右室起源的室性心律失常为其特征性的心电图改变,QRSd1/QRSd2≥1.2、室壁阻滞、右胸导联S波升支时间≥55ms有助于该病的诊断,经导管射频消融治疗室性心动过速成功率低。     

右心室室性心动过速患者时域法微伏级T波电交替特征及其临床意义

目的探讨右心室室性心动过速患者时域法微伏级T波电交替（MTWA）特征及其临床意义。方法采用活动平板时域法分别对35例致心律失常性右心室心肌病（ARVC）患者[其中男性28例,平均年龄（38．6±11,0）岁]、10例特发性右心室室性心动过速（IRVT）患者[其中男性7例,平均年龄（41．9±15．4）岁]和60例健康对照者[男性42例,平均年龄（41．0±14．9）岁]进行MTWA检测,记录胸前V1～V6导联的MTWA值,确定胸前各导联的最大值,以Max Valt表示。分析比较不同组别各导联MTWA值及Max Valt值的差异。结果ARVC组各导联MTWA值和Max Valt值均明显高于对照组（P〈0．01）;IRVT组各导联的MTWA值和Max Valt值比对照组升高,但差异无统计学意义（P〉0．05）;ARVC组和IRVT组比较,V4导联MTWA值及MaxVah值明显较高（P〈0．05）;接受者操作特性（receiver operating characteristic,ROC）曲线分析表明,以Max Valt〉11．5μV鉴别诊断ARVC的敏感性为74．3％,特异性为80．0％;ARVC组中,近一年内有持续性室速发生的患者较无室速发作患者V2～V6导联的MTWA值以及Max Valt值的差异有统计学意义。结论渐量修正平均时域法检测显示,ARVC患者MTWA值和Max Valt值均明显升高．MTWA佰可以反映ARVC患者近期室性心动过速的发作。     

致心律失常性右心室心肌病右胸导联QRS时间延长的临床意义

目的探讨致心律失常性右心室心肌病右胸导联QRS时间延长的临床意义。方法收集致心律失常性右心室心肌病25例,分析临床和常规体表心电图特征,测量QRS时间、Q-T间期等各项参数,计算右胸导联(V1～V3)和左胸导联(V4～V6)QRS时间的平均值及两者之比。结果25例致心律失常性右心室心肌病病例的年龄(37.1±15.0)岁,其中男性12例,女性13例。常规心电图中Epsilon波阳性(第1组)11例(44.0%),其中63.6%(7/11)见于V1～V3导联;Epsilon波阴性14例(第2组)。所有患者的平均QRS离散度为36.3±27.2ms,Q-T离散度为57.2±27.1ms。平均QRS时间右胸导联[QRS1=(V1+V2+V3)/3]为0.13±0.03s,而左胸导联[QRS2=(V4+V5+V6)/3]为0.11±0.02s,差异有非常显著性意义(P<0.01)。QRS1/QRS2值为1.0～1.9,其中16例(61.5%)≥1.2。发生晕厥第1组8例(72.7%),而第2组4例(28.6%)(P<0.05)。两组的QRS1分别为0.14±0.04s、0.13±0.02s,QRS2分别为0.12±0.03s和0.11±.017s,QRS1/QRS2值为1.22±0.26和1.21±0.13,差异均无显著性意义(P>0.05)。结论右胸导联平均QRS时间延长有助于诊断致心律失常性右心室心肌病,但能否作为致心律失常性右心室心肌病预后的不良因素尚须进一步研究。     

家族史在致心律失常性右心室心肌病危险分层中的地位

目的 探讨家族史在致心律失常性右心室心肌病(ARVC)危险分层中的地位.方法 根据1994年ARVC诊断标准,纳入34例ARVC先证者,男性26例,女性8例,平均年龄(38±15)岁.对其家族成员行临床筛查,项目包括:(1)心电图V1～V3导联QRS≥110 ms、V1～V3导联S波升支≥55 ms、Epsilon波、T波倒置(V1～V3导联倒置)、(V1+V2+V3)/(V4+V5+V6)QRS≥1.2、V1～V3导联与V6导联QRS差值≥25 ms,QRS离散度≥40 ms,QT离散度≥65 ms;(2)动态心电图记录室性早搏≥2000个/24 h或室性心动过速(VT);(3)超声心动图记录双心房、双心室及右心室流出道、流人道内径大小.比较ARVC家族史和上述各项临床参数的关系.分类变量用Fisher检验,连续变量使用t检验.P≤0.05为差异有统计学意义.结果 34例ARVC先证者中55个家族成员接受评估,男性28例(6例诊断ARVC)、女性27例(3例诊断ARVC),平均年龄(35±16)岁.8例先证者有家庭成员受累,其中5例有左束支阻滞形室性心动过速(LBBB-VT,63%);26例先证者家庭成员无受累,其中20例有LBBB-VT(77%),P=0.649.家族史和室性心动过速的发生筹异无统计学意义.结论 家族史并不能反映ARVC的危险程度.     

致心律失常性右心室心肌病的QRS及QT离散度研究

目的　探讨致心律失常性右心室心肌病 (arrhythmogenicrightventricularcardiomyopathy ,ARVC)危重患者、家系中无症状患者及家系中可疑患者的QRS及QT离散度的存在规律。方法　按欧洲心脏病学会 (ESC)的诊断标准 ,选择有室性心动过速、晕厥或心脏骤停 (cardiacarrest)史的ARVC患者 2 5例为危重组 ,家系调查发现的家系中无明显症状的ARVC患者 16例为无症状组 ,家系中高度怀疑为ARVC但尚未达到诊断标准的 18例为可疑组 ,正常对照组为 14例。同步记录标准 12导联心电图。测量每个导联QRS时限 ,记录 12导联中的QRS时限最大值 (QRSm ,最长的 1个QRS值 )、QRS离散度 (QRSd ,12导联中最长的 1个QRS值减最短的 1个QRS值 )及QRS时限平均值 (QRSa)。测量每个导联QT间期 ,记录 12导联中的QT最大值 (QTm ,最长的 1个QT间期 )、QT平均值 (QTa)、QT离散度 (QTd ,导联中最长的 1个QT值减最短的 1个QT值 )、校正QTd(QTcd)及校正QTm(QTcm)。比较各组各指标的差异。结果　可疑组的年龄低于对照组、危重组与无症状组。 4组之间QRSd差异无显著性。QTd在危重组为 (6 9 6± 4 1)ms,在无症状组为 (77 3± 5 7)ms均显著高于对照组 (5 5 4±6 3)ms(P均为 0 0 0 3) ;危重组与无症状组差异无显著性。QRSm、QRSa、QTa、QTcd、QT     

致心律失常性右心室心肌病的流行病学研究和家系随访

目的　通过收集致心律失常性右心室心肌病 (arrhythmogenicrightventricularcardiomyopathy ,ARVC)的散发人群资料和随访ARVC家系 ,提供ARVC的流行病学资料并发现病情变化 ,寻找疾病规律。方法　统计就诊 33例ARVC患者的流行病学资料。分别随访 2个ARVC家系 3 5年和 4 5年。询问随访前后每一家系成员病史 ,做心电图、二维超声心动图和心室晚电位 ,必要时进行 2 4h动态心电图检查 ,了解病情变化。根据欧洲心脏病学会诊断标准作出诊断。结果　 33例ARVC患者中男性 18例 ,女性 15例 ,平均诊断年龄 (4 2 8± 14 9)岁 ,2 0～ 6 0岁者占 88%。随访的第 1个家系共有 2例患者 ,均猝死。另 1个家系随访结束后共发现 11例患者。随访中患者症状无明显变化 ,但 2名家系成员新确诊患病 ;1例患者心室晚电位变为阳性 ;1例患者心电图右胸前导联T波倒置导联数增加 ,3例T波倒置由右胸前导联向左胸前导联扩展 ,3例T波异常累及右胸前导联和左胸前导联 ;1例患者Epsilon波增宽 ,1例患者新出现Epsilon波 ;4例患者V1 导联QRS时限增加。扩展调查此家系又发现 2例患者和高度怀疑的 1例患者 ,先证者外祖父母为近亲结婚。结论　ARVC男女发病率相似 ,好发于青壮年 ;是一进展性疾病 ,虽是右心室疾病 ,可能多有侵犯左心室 ,易致猝死     

致心律失常性右室心肌病的心电图特征和临床观察

目的观察致心律失常性右室心肌病(ARVC)的心电图特征及临床特点。方法选取我院2012年5月~2015年2月收治的致心律失常右室心肌病患者50例。全部患者窦性心律下常规同步12导联心电图扫描,放大全部图像结果,测量心电图参数,将精确度升高到1 ms。结果出现Epsilon波4例(28.0%),V1~V3导联QRS平均时限为(121±20)ms,其中41例(82%)患者110 ms;V4~V6导联QRS平均时限为(104±21)ms;QRSd1/QRSd2=1.15。出现T波倒置27例,S波升支时间≥55 ms 21例,室壁阻滞22例,持续性或是非持续性心动过速29例。结论 ARVC多见于青年男性,多数ARVC患者会出现Epsilon波异常、V1~V3导联QRS时限110 ms、T波倒置、QRSd1/QRSd21.2、室壁阻滞、S波升支时间延长等,在诊断时应结合患者个人情况、家庭情况、临床症状等进行综合判定。     

Differentiating arrhythmogenic right ventricular cardiomyopathy from right ventricular outflow tract ventricular tachycardia using multilead QRS duration and axis.

BACKGROUND: Ventricular tachycardia (VT) resulting from arrhythmogenic right ventricular cardiomyopathy (ARVC) may be difficult to differentiate from idiopathic right ventricular outflow tract (RVOT) VT. OBJECTIVES: The purpose of this study was to investigate the hypothesis that QRS characteristics would be different in ARVC because of altered conduction through abnormal myocardium. METHODS: In 24 RVOT VT patients (18 women and 6 men; age 42 +/- 10 years) and 20 ARVC patients (12 women and 8 men; age 38 +/- 14 years), mean QRS duration, frontal plane axis, and precordial R-wave transition were measured in 12-lead ECGs recorded during VT. RESULTS: Mean QRS duration was longer in all 12 leads in ARVC patients. A significant difference was noted in leads I, III, aVL, aVF, V(1), V(2), and V(3) (P <.05). Leads I and aVL had the largest mean difference between ARVC and RVOT VT patients of 17.6 +/- 4.7 ms and 15.8 +/- 7.5 ms, respectively (P <.0001). Lead I QRS duration > or =120 ms had a sensitivity of 100%, specificity 46%, positive predictive value 61%, and negative predictive value 100% for ARVC. The area under the receiver operating characteristic (ROC) curve was 0.89. The addition of mean QRS axis <30 degrees (R相似文献   

心电图评价致心律失常性右心室心肌病病变程度的临床价值

目的 分析致心律失常性右心室心肌病(ARVC)患者的病变程度与心电图表现之间的关系.方法 分析61例已确诊的ARVC患者,根据心脏核磁共振成像(MRI)检查结果,将其按病变侵犯部位分为右心室局部病变组、右心室弥漫病变组、双心室病变组,分析比较三组的心电图特征.结果 心脏MRI结果显示右心室局部病变组19例(31%),右心室弥漫病变组28例(46%),双心室病变组14例(23%).心电图正常者3例,三组中各1例.伴有Epsilon波的患者24例(39%)、V1～V3导联的QRS波时限≥110 ms的患者21例(34%)、V1～V3导联S波升支≥55 ms的患者17例(28%)、完全右束支传导阻滞的患者10例(16%)、病理性Q波的患者9例(15%),这些指标的发生率均随病变程度的加重而增高(右心室局部病变组＜右心室弥漫病变组＜双心室病变组).Epsilon波、V1～V3导联的QRS波时限≥110 ms、完全性右束支传导阻滞(RBBB)、病理性Q波的发生率在双心室病变组中要高于右心室局部病变组,且两组间比较差异有统计学意义(P＜0.05).V1～V3导联S波升支≥55 ms的发生率在双心室病变组中要高于右心室局部病变组,且两组间比较差异有统计学意义(P＜0.05);在双心室病变组要高于右心室弥漫病变组,且两组间比较差异均有统计学意义(P均＜0.05).一度房室传导阻滞的发生率在双心室病变组中要高于右心室弥漫病变组,且两组间比较差异有统计学意义(P＜0.05).右心室局部病变组患者心电图T波倒置多局限于V1导联,右心室弥漫病变组和双心室病变组T波倒置多数表现于胸前导联V1～V3或超过V3导联的胸前导联、以及下壁导联.结论 心电图正常并不能排除ARVC.ARVC患者T波倒置在12导联心电图上具有很高的发生率,并且T波倒置在胸部导联的延伸与病变程度是相关的,T波倒置的范围可以提示ARVC病变累及的程度.

Abstract：

Objective To analyze the relationship between electrocardiographic (ECG) features and disease severity in patients with the arrhythmogenic right ventricular cardiomyopathy (ARVC). Method The study group consisted of 61 subjects with a definite diagnosis of ARVC on the basis of published guideline criteria and patients were divided into 3 subgroups according to the extent of diseased myocardium defined by cardiac magnetic resonance imaging (MRI): Group A: local involvement (n = 19, 31% ), Group B: diffuse involvement of whole right ventricle ( n = 28, 46% ) and Group C: involvement of both right and left ventricles ( n = 14, 23% ). Results Normal electrocardiogram was shown in 1 patient in each group.Epsilon wave was detected in 24 (39%) patients, QRS duration was prolonged [≥ 110 ms( V1 -V3 )] in 21 (34%) patients, S-wave upstroke was prolonged (≥55 ms) in 17 (28%) patients, complete right branch bundle block was evidenced in 10 ( 16% ) patients and pathologic Q waves was found in 9 ( 15% ) patients. The incidence of above abnormal ECG changes was increased in proportion to the degree of disease severity (group A ＜ group B ＜ group C). Incidence of Epsilon wave and prolonged QRS duration [≥ 110 ms (V1 - V3 )] were significantly higher in Group C than in Group A. Incidence of prolonged S-wave upstroke ( ≥55 ms) was significantly higher in Group C than in Group A and Group B. T-wave inversion in V1 leads was often found in Group A. T-wave inversion in inferior leads ( V1 - V3 leads or beyond V3 ) was often presented in Group B and Group C. Conclusions Normal ECG does not exclude the possibility of diagnosis of ARVC. The extent of T-wave inversion in the precordial leads and incidence of Epsilon wave, prolonged QRS duration [≥ 110 ms (Vt -V3 )] and prolonged S-wave upstroke ( ≥55 ms) were related to degree of disease severity in patients with ARVC.     

致心律失常性右心室心肌病的心电图特征

目的探讨国人致心律失常性右心室心肌病患者临床心电图特征。方法分析32例致心律失常性右心室心肌病患者体表心电图各项参数。结果心电图记录到Epsilon波12例,QRS时间（V1＋V2＋V3）／（V4＋V5＋V6）≥1.2共15例,终末激动时间延长17例,出现QRS波群碎裂23例,可见异常Q波8例,V1～V3T波倒置且不存在束支传导阻滞14例,完全性右束支传导阻滞3例,不完全性右束支传导阻滞1例。28例记录到室性心动过速。结论Epsilon波、QRS时间（V1＋V2＋V3）／（V4＋V5＋V6）≥1.2、终末激动时间延长≥55ms及QRS波群碎裂是致心律失常性右心室心肌病特征性的体表心电图改变。     

Electrocardiographic (ECG) clues to differentiate idiopathic right ventricular outflow tract tachycardia (RVOTT) from arrhythmogenic right ventricular cardiomyopathy (ARVC)

Introduction

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic cardiomyopathy that most commonly affects young adults. The most commonly observed reason of death in patients suffering from ARVC/D is sudden cardiac death (SCD). On the other hand, idiopathic right ventricular outflow tract tachycardia (RVOT VT) usually has a benign course. Both of the entities may have ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern and inferior axis. We tried to propose new discriminating electrocardiographic indices for differentiation of foretold entities.

Material and method

This was a retrospective study. We reviewed records of patients admitted between 2003 and 2012 with the diagnosis of either ARVC/D or RVOT VT that presented with VT (LBBB morphology).

Result

A total of fifty nine patients (30 RVOT VT and 29 ARVC/D) were enrolled. In ARVC/D group, men were dominant while the reverse was true of RVOT VT. Palpitation was more common in the RVOT VT group (90% vs. 66.7%), but aborted SCD and sustained VT were more common in ARVC/D group. The new ECG criteria proposed by us mean QRS duration in V1–V3, QRS difference in right and left precordial leads, S wave upstroke duration, JT interval dispersion, QRS and JT interval of right to left precordial leads were all significantly longer in ARVC/D when compared to RVOT VT patients (p < 0.001).

Conclusion

The proposed ECG criteria can be used for non-invasive diagnosis of ARVC/D and incorporation in the future updates of ARVC/D task force criteria.     

Long‐Term Follow‐Up After Radiofrequency Catheter Ablation of Ventricular Tachycardia: A Successful Approach?

INTRODUCTION: Radiofrequency ablation (RFCA) of ventricular tachycardia (VT) is a potential curative treatment modality. We evaluated the results of RFCA in patients with VT. METHODS AND RESULTS: One hundred fifty-one consecutive patients (122 men and 29 women; age 57 +/- 16 years) with drug-refractory VT were treated. Underlying heart disease was ischemic heart disease in 89 (59%), arrhythmogenic right ventricular cardiomyopathy (ARVC) in 32 (21%), and idiopathic VT in 30 (20%; left ventricle in 9 [30%]; right ventricle in 21 [70%]). Ablation was performed using standard ablation techniques. Three hundred six different VTs were treated (cycle length 334 +/- 87 msec, 2.0 +/- 1.4 VTs per patient). Procedural success (noninducibility of VT after RFCA) was achieved in 126 (83%) patients (70 ischemic heart disease [79%]; 28 ARVC [88%]; 27 idiopathic VT [93%]). Procedure-related complications (< 48 hours) occurred in 11 (7%) patients: death 3 (2.0%), cerebrovascular accident 2 (1.3%), complete heart block 4 (2.6%), and pericardial effusion 3 (2.0%). Thirty-three (22%) patients received an implantable cardioverter defibrillator (because of hemodynamic unstable VT, failure of the procedure, or aborted sudden death). During follow-up (34 +/- 11 months), VT recurrences occurred in 38 (26%) patients (recurrence rate: 19% in successfully ablated patients and 64% in nonsuccessfully ablated patients; P < 0.001). During follow-up, 12 (8%) patients died (heart failure 8, unknown cause 1, noncardiac cause 3). CONCLUSION: RFCA of VT can be performed with a high degree of success (83%). The long-term outcome of successfully ablated patients is promising, with a 75% relative risk reduction compared with nonsuccessfully ablated patients. During follow-up, only one patient died suddenly, supporting a selective ICD placement approach in patients with hemodynamically stable VT.     

Electrical alternans in wide complex tachycardias

The occurrence of electrical alternation of 0.1 mV or greater of the QRS or T wave was analyzed in 156 electrocardiograms that showed wide QRS complex tachycardias from 91 patients. One hundred thirty-six ventricular tachycardias (VT) were recorded from 74 patients and 20 supraventricular tachycardias (SVT) from 17 patients. Alternans was present in 42 tracings (27%) from 35 patients (38%) and was equally frequent in the patients with VT (39%) and those with SVT (35%). Alternans occurred in 36 VTs (27%) and 6 SVTs (30%). Tachycardias with alternans had a shorter mean cycle length than tachycardias without alternans (339 +/- 53 vs 368 +/- 85 ms, p less than 0.05), but were not associated with a particular QRS morphology or axis. Alternans was most frequent in leads V2 and V3 and was seen in more leads during SVT than VT (7.2 +/- 2.6 vs 3.7 +/- 2.5, p less than 0.005). All SVTs with alternans incorporated an atrioventricular bypass tract. Electrical alternans occurs frequently in wide QRS tachycardias. Alone, it does not help differentiate VT from SVT. SVTs utilizing bypass tracts frequently show alternans even if the QRS is wide, and this finding may be useful in determining the mechanism of SVTs with aberrant intraventricular conduction.     

Prevalence of electrocardiographical signs of right ventricular arrhythmogenic dysplasia

Right ventricular arrhythmogenic dysplasia (RVAD) is a state with high risk of sudden death in young patients. Early diagnosis of RVAD can facilitate sudden death prevention. AIM: To assess prevalence of electrocardiographical signs of RVAD among children with "idiopathic" tachyarrhythmias. MATERIAL: Patients without organic heart disease or overt noncardiac causes of arrhythmia aged 4-17 years (n=134, mean age 12+/-4.5 years, 56 girls and 76 boys) including 82 patients with >5000 extrasystoles VE 24 hours and 52 patients with ventricular tachycardia (VT). All patients had QTc interval <440 ms. METHODS: Twelve lead ECGs from all patients were analyzed for determination of morphology of arrhythmia and presence of "major" (epsilon wave and QRS duration >110 ms in V(1)-V(3)) and "minor" (VT with left bundle brunch block - LBBB, VE >1000/24 hours, T-wave inversion in V(2) and V(3)) diagnostic criteria for RVAD (W.McKenna, 1994; D.Corrado, 2000). RESULTS: ECG signs of RVAD were found in 28 of 58 (48.3%) of patients with VE and in 1 of 24 patients (4.2%) with atrial extrasystoles. Among patients with VE 27 (96.4%) had extrasystoles with LBBB morphology and 1 (3.6%) - with right bundle brunch block (RBBB) morphology. Combination of major and minor criteria sufficient for diagnosis of RVAD was found in 19% (8 of 42) of patients with VE with LBBB. Among 52 patients with VT 21 had polymorphic VT and 31 - monomorphic VT (16 with LBBB and 15 with RBBB). Epsilon wave was present in 56.3% (9/15) of patients with monomorphic VT and LBBB, in 4.8% (1/21) of patients with polymorphic VT and in none of the patients with monomorphic VT and RBBB. QRS duration exceeded 110 ms in 2 (12.5%), 2 (9.5%) and 0 patients among those with monomorphic VT and LBBB, polymorphic VT, and monomorphic VT and RBBB, respectively. Among patients with monomorphic VT and LBBB 37.5% (6/16) had combination of ECG criteria sufficient for diagnosis of RVAD. In 3 patients epsilon wave was registered in lead V(1) immediately prior to VT and disappeared after VT cessation. Implications. It can be suggested that presence of polymorphic VT or VE with LBBB morphology and specific ECG changes (first of all epsilon wave and QRS widening) distinguishes a group of patients with high risk of RVAD which requires thorough cardiological examination and dynamic observation.     

Electrocardiographic predictors of failure and recurrence in patients with idiopathic right ventricular outflow tract tachycardia and ectopy who underwent radiofrequency catheter ablation

This study reports new electrocardiographic (ECG) predictors of radiofrequency catheter ablation failure and recurrence in idiopathic right ventricular outflow tract (RVOT) ventricular tachycardia (VT) or ectopy based on 91 consecutive patients. Procedural success and failure rates were 85% (77/91) and 15% (14/91), respectively. Twenty three percent (18/77) had recurrence during the follow-up period of 1 to 120 months (mean 56 +/- 31 months). Baseline RVOT VT/ectopy on 12-lead ECG taken prior to ablation from 91 patients were retrospectively analyzed. Ablation performed with RVOT ectopy (isolated ectopies, bigeminy, trigeminy, or couplets) as template arrhythmia was more likely to fail (30% vs. 8%, P =.02) as opposed to RVOT VT (sustained or nonsustained). VT/ectopy-QRS morphology variation was more observed in failed ablations (36% vs. 7%, P =.001). Significantly wider mean VT/ectopy QRS in leads I, II, AVR, V2, V3, V5, and V6 were noted in failed ablation group. Mean R wave amplitude reached statistical significance only in lead II (22.0 +/- 5.1 mV for failed vs. 17.8 +/- 5.2 mV for successful outcomes; P =.009). QRS morphologic variation (47% vs. 16%; P =.009) was the only statistically significant ECG to be more common in patients with arrhythmia recurrence. In conclusion, ablation with ectopy over VT as template arrhythmia, presence of QRS morphologic variation, wider mean QRS width, and taller mean R-wave amplitude in lead II were identified ECG predictors of failed RVOT VT/Ectopy ablation. The only ECG predictor of recurrence was the presence of RVOT VT or ectopy QRS morphologic variation.